September 52371, 52425; November 52464-52468, 52518-52520, 52552-2555, 52598-52605; December 52642-52645

Baldwin reported that these huge locomotives were intended for the 2.4% grades in the Cumberland Division, over which they would haul long, loaded trains of coal cars.

The cylinders used a combination of 14" (356 mm) piston valves for the HP cylinders actuated by Baker gear and Allen balanced slide valves for the LP cylinders operated by Walschaert's gear. When the LP cylinders were rebuilt with piston valves, they were opened by Baker gear. (Thanks to Chris Hohl for providing an example of the weird-looking result.)

Definitely intended for main-line service, these big articulateds were able to negotiate curves as sharp as 22 deg. Total weight distribution varied by only 1,100 lb between the front and rear engine units.

Several classes beginning with 15 EL-1 (1916) and followed by 15 EL-2 (7200-7214 in 1916), 30 EL-3 (7115-7144 in 1917) and 26 EL-5 (7145-7170 in 1919-1920) -- all by Baldwin.

All surviving locomotives were converted from 1927 on after the prototype demonstrated a considerable improvement in pulling power; see Locobase 305.

The last of these left service in 1954.

Class EL-3a/EL-5a (Locobase 305)

Data from tables in 1930 Locomotive Cyclopedia.

These were B&O rebuilds of B&O compound Mallets (Locobase 439) to four-cylinder simple-expansion machines beginning in 1927. 64 engines were converted altogether, all to the same powerful standard.

Compared to the EL-6a conversion (Locobase 3556), these locomotives didn't work quite so hard, but steamed as easily. All four cylinders used 14" (356 mm) piston valves.

Smaller drivers undoubtedly confined them to hill work, where they served until the early 1950s.

Class EL-6a (Locobase 3556)

Data from Wiener (1930) supplemented by B&O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. (Thanks to Chris Hohl for correcting the valve gear ID.)

These were simpled conversions of SAL 2-8-8-2s (Locobase 15148) that had come onto the B&O in 1922. They had a relatively high driver diameter and a hard-worked, but relatively free-steaming boiler. The last of these left service in 1954.